4E analysis and evaluation of a steam power plant full repowering in various operations

Abstract

ABSTRACT In this paper, full repowering of a 320 MW steam power plant was investigated in Bandar Abbas. Due to unavailability of natural gas in the winter, LNG, Diesel, and Heavy fuel were examined as alternative fuels. The energetic, exergetic, exergoeconomic, and exergoenvironmental (4E) analyses were performed for old and repowered cases. The exergoenvironmental analyses were done based on the Life Cycle Assessment in SimaPro software. The net power, fuel consumption, costs, and environmental impacts were calculated by considering different fuels for each season. To better demonstrate the plant performance, the exergy destruction level (EDL) and the exergy cost destruction level (ECDL) were defined and applied as EDL/ECDL. To perform this analysis, a computer program was developed that could predict the base cycle and repowered cycle behaviors for different operating conditions with relative errors of less than 1.85%. Results demonstrated a 16% increase in the overall cycle efficiency, a 12% decrease in the methane consumption, and a 3% elevation in the net power using the LNG fuel.